Adoctor who specializes in diagnosing and treating diseases and disorders of the eyes and vision.

Ocean waves move up and down in circles, but transmit horizontally toward the shore.

15 ! come and answer! a(n) is the general term for an infectious disease that has spread across a city, region, or country.

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important